The restaurant business isn’t for the faint of heart. What’s hip and trendy one day is out of fashion the next. The food may be excellent, but partnerships dissolve, the chef quits, the diners flock to the newest hot spot.

What keeps a restaurant in the game for the long haul? Ask some of Denver’s best-known and longest-enduring restaurateurs — Lee Goodfriend and David Racine of Racines and Dixons; Mark Greenberg of The Market at Larimer Square; Daisy and Mack Shead Sr. of M&D’s Cafe; Johnny Hsu of the Imperial and the Palace; Noel Cunningham of Strings; Holly Arnold Kinney of The Fort, and Rosa Linda Aguirre of Rosa Linda’s Mexican Cafe — and you’ll get answers as different as their restaurants.

None of them would tell you it’s been easy. All have made mistakes — some costly, some bruising, some a blow to the spirit, some nearly game-ending. But, says Greenberg, “This is a labor of love.”

Here’s how Denver’s restaurant veterans made it. They should know; each of them has been in business at least 25 years.

Start with basics

All of our restaurateurs agreed that to get in the game, you need a few basics: good food, quality service, consistency, a comfortable atmosphere. Especially important: treating your own employees well. “I think you can feel it,” says Goodfriend of Racines. Greenberg agrees: “My pot washer has been here 11 years. I have employees who have been here for 25 years.”

Be stubborn

When Aguirre moved into her space in the Highland neighborhood in 1984, there were small bars on every corner and some not-so-savory types who came with them. It was not a destination neighborhood, but Aguirre says, “We wanted a place close to home where my kids go to school, and we’re part of the community.” Determined, she did what she had to do, even staying open until 3:30 a.m., “just to pick up the nightclub crowd. I was young and daring. And I am so stubborn.”

Find your niche

When the Sheads opened M&D’s Cafe in Five Points in 1977, they had a simple concept: barbecue. “They just knew what they wanted to do,” says daughter Deborah, who, along with brother M.J. and sister Rena, helps run the family business. Adds her mother, Daisy, “We weren’t worried about the competition. I didn’t know there was competition.” Despite the famous Daddy Bruce’s barbecue nearby, M&D’s was an immediate hit.

When Goodfriend and her partners David Racine and Dixon Staples first opened Racines in 1983, she says, “We thought, let’s open it up for breakfast.” But breakfast was not an overnight sensation. “It was immediately packed at lunch — I think it was the location — but breakfast took time.” Persistence paid off: Customers stack up for breakfast now.

Take a chance

Hsu opened the Imperial Chinese Restaurant in 1985, when Denver’s economy was tanking. “I saw that the economy was bad,” he says, “but people still have to eat, and they want the best.” At the time, Hsu was running another Chinese restaurant in southeast Denver, but saw opportunity. “I said I can do better — higher-end in service and atmosphere. (But the restaurant) was already 5 years old, and you can’t change a restaurant midstream. You can lose your clientele. It was easier to start over.” Hsu knew it was a gamble: “I played the odds.”

Buy the building if you can

Greenberg is the only restaurateur interviewed who still leases his space. “This block (on Larimer Square) is worth so much that buying the building would have been exorbitant.” The others felt that buying their buildings gave them a little breathing room, even bringing in some added revenue. Aguirre leases part of her building to the hip Squeaky Bean restaurant. Noel Cunningham of Strings leases space to D-Bar, the dessert emporium. “I felt there was a light at the end of the tunnel (when I bought the building),” says Cunningham, “and it wasn’t a train.”

Provide parking

Every one of the restaurateurs cited convenient parking as important. At Racines, the owners bought a parking lot and offer a courtesy valet service for prime time. “It’s called the hospitality business,” Racine says. “Parking is critical. We spent money taking care of the customer on parking, because it begins with that.”

Don’t go changin’ . . . too much

Holly Arnold Kinney kept her father’s — Sam Arnold’s — original vision alive at The Fort, and enhanced it. “We look at the foods of the 19th century and modernize them. The movement of regional and historic cuisine, farm to table, is very much the cuisine of The Fort. We have the foods of the pioneers, American Indians and old Southwestern Hispanic cultures — our core menu, but then we innovate. We put buffalo empanadas on the menu and it’s the No. 1-selling appetizer.”

“Seven years ago, (Strings was) old news,” Cunningham says. “We either had to reinvent ourselves or close.” He chose to stay open, hiring a group of young people to carry him “kicking and screaming into the new social way of communicating because I’m a dinosaur.” It was the right decision. “I love watching these young kids put their heart and soul in it.” Now that the East 17th Avenue stretch has become hip, says Cunningham, “We’re becoming the neighborhood restaurant that I always wanted to be.”

Reach out

Aguirre considers Rosa Linda’s “the heart of the Highlands.” She and her family have served a free Thanksgiving dinner for the needy each year since 1985. When the restaurant was being updated and it took longer than expected, threatening to spill over into Thanksgiving, Aguirre refused to even consider canceling the annual event. “I said, ‘I’m cooking Thanksgiving dinner, even if I have to do it outside with a grill.’ “

At The Market, Greenberg loves lingering customers. “The Market represents what Denver is — friendly, not too rushed. If there’s no table, I say, ‘You mind if this person sits with you?’ “

Close with caution

When Hsu moved the Imperial to its present location, he kept the old Imperial operating while he built his new building. The reason he moved: more parking. But he was careful to change the operation without missing a beat. “We didn’t even close down one day. We moved overnight.”

M&D’s Cafe wasn’t so lucky. When the restaurant closed for renovations nine years ago, it took six months to reopen. “A rumor went around that we were closed for good,” says daughter Rena Shead. The family finds that the rumor mill cranks up every so often. “We need to be more aggressive in our marketing,” says M.J. “The neighborhood is younger now. They don’t know we’re here.”

Keep it in check

To help a fellow chef and friend, Hsu opened Le Chine, offering a completely different menu than the Imperial. “It got good reviews and it did OK business,” says Hsu, “but we were too high-priced at that time.” Plus he found that he was competing with Imperial. Le Chine closed. In hindsight, Hsu says, he opened Le Chine for the right motivation, but the wrong reasons. “It wasn’t about the money or my ego. It was just literally helping a friend.”

At age 60, and after more than 30 years in the business, Goodfriend says, “my experience is that more is not better. It’s hard to focus on six or seven restaurants at once.”

Be trendy, but not too trendy

The restaurateurs agree that it’s important to watch trends, without being, well, trendy. Changing tastes require menu adjustments. Hsu has added vegetarian equivalents of his most popular dishes. “From time to time, we have new dishes. If the public accepts it, we add it permanently to the menu, but it would be suicidal to take off dishes like sesame chicken. No way!”

Rosa Linda’s has always had gluten- free options, “just by the nature of the beast,” and many of the dishes now qualify for the Heart Smart seal. But Aguirre says, “We won’t change certain items just to please people.”

Says Greenberg, “You can only worry about what goes on in your walls; be creative, and keep up with the trends.”

Wining, dining celebs and politicians

All the restaurants in this story have hosted celebrities and politicos. The Fort was chosen to host a dinner for world leaders at the Summit of the Eight in 1997. Vice President Joe Biden stopped by M&D’s Cafe with Sen. Michael Bennet in 2009; the first President George Bush swung by for soup and a turkey sandwich at The Market in 1992. Federico Peña is a longtime customer of Rosa Linda’s; and Racines has been a mainstay of numerous Colorado governors and local TV personalities. And then there are the celebrities and politicians who have passed through Strings: Paul McCartney, the Rolling Stones, Ted Kennedy.

25 years or older

More than a handful of Denver-area family owned restaurants have been around a quarter-century or more. Here is a sampling: